1. Field of the Invention
The present invention relates to electronic components. In particular, the present invention relates to electronic components with shielding cases accommodating surface mount devices mounted on the substrates in the same manner as high-frequency composite components such as voltage controlled oscillators (VOCs) or phase-locked loop (PLL) modules, and relates to methods of manufacturing the same.
2. Description of the Related Art
FIG. 6 is a perspective view of a known electronic component with a shielding case (See Japanese Unexamined Patent Application Publication No. 2001-148594). This electronic component includes a substrate 51, a surface mount device (not shown) mounted on the top surface 51a of the substrate 51, and a shielding case 53 accommodating the substrate 51 and the surface mount device.
The substrate 51 includes four side surfaces each having a plurality of catching grooves 54 for mounting the shielding case 53. The catching grooves 54 are parts of through holes, and electrodes are provided on the inner surfaces of the catching grooves 54. Land electrodes 58 are formed on the top surface 51a of the substrate 51 around the catching grooves 54 for electrical connection between the substrate 51 and substrate-opposing portions 53a of the shielding case 53.
The shielding case 53 includes a casing body 55 accommodating the surface mount device (not shown), and a plurality of catching pieces 56 fitted into the catching grooves 54 of the substrate 51.
The catching pieces 56 formed on respective sides of the shielding case 53 are soldered to the electrodes formed on the inner surfaces of the catching grooves 54 while the catching pieces 56 are fitted into the catching grooves 54 of the substrate 51. In this manner, the shielding case 53 is fixed to the substrate 51.
In order to produce electronic components with shielding cases having the above-described substrate, surface mount devices are mounted on a motherboard that will be divided into a plurality of substrates later, and shielding cases are fixed to the motherboard by fitting and soldering catching pieces of shielding cases to through holes bored through the motherboard. The motherboard is then cut with a cutting device such as a dicer at predetermined positions where the through holes are divided into the catching grooves. In this manner, the electronic components with the shielding cases are produced.
Therefore, intervals between two adjacent shielding cases mounted on the motherboard must be sufficiently wide such that the cutting device, for example, a dicing blade, can pass through the intervals. In consideration of various errors such as a positional misalignment during dicing, an initial positional misalignment of the cutting device, and a dimensional deviation of the motherboard, the intervals should include margins to compensate for the above-described errors in addition to cutting allowances depending on the width of the dicing blade. As a result, the number of the intervals between two adjacent shielding cases is increased with the number of the electronic components produced from one motherboard. This leads to a reduction in the available area of the motherboard and an increase in cost.